1. Field of the Invention
The invention relates to devices for producing controlled movement of a point or medium in space.
2. Description of the Prior Art
A variety of spacial mechanisms or devices for producing controlled motion of solid elements and light beams in space have been proposed. Numerous mechanical devices for controlling movement of mechanical elements have been proposed and are utilized in various types of robotic devices, commonly used in computer controlled manufacturing operations. These computer controlled machines tend to be expensive, bulky, and in some cases, lack adequate stability, speed, accuracy and reliability needed for many applications, especially if low cost is necessary. Various required motions in known devices are provided by means of a series of arms and pivot joints to provide the degrees of freedom needed for many robotic applications. The arm "stiffness" of the articulated arm members and the strength and positioning accuracy of such devices is determined by the number of and length of sequential extensions of articulated members from a main support frame. The strength and accuracy of such articulated arms tends to be further degraded with each successive arm and joint of such articulated structures, resulting in multiplication magnitudes of errors in positioning the ends of the arm. Typically, pneumatic or hydraulic actuators are utilized to produce pivoting of each arm member relative to the previous one, thereby limiting applications of the spacial mechanisms to those environments in which pneumatic or hydraulic power sources are available. Although the above disadvantages are not critical for many general applications in which relatively large extent of motion is required, smaller and more precise operations that often need to be performed by robotic devices require far greater precision than is capable of being attained at reasonable cost using prior articulated devices.
Accordingly, it is a primary object of the invention to provide an improved spacial mechanism and method which avoids the locational inaccuracies and weaknesses that result when articulated arm structures are utilized.
It is another object of the invention to provide a spacial mechanism and method which is relatively inexpensive and yet provides a high degree of precision, locational accuracy and reliability.
Previous spacial mechanisms typically have required a large number of computational steps to provide the control signals necessary to move a utilization point from one particular location to another described location.
Accordingly, another object of the invention is to provide a computer controlled spacial mechanism which requires a minimum number of computations to generate the control signals necessary to move a utilization point of the spacial mechanisms from one predetermined location to another predetermined location.